This invention is directed to an overtemperature monitor and integrator apparatus for determining the amount of overtemperature to which a gas turbine or other temperature sensitive equipment is subjected. It has a temperature sensor and an indicator which shows the integrated product of overtemperature and time. Signal processing is accomplished electronically.
The life of many types of prime movers, such as gas turbines, is determined by the duration and excursion of the temperature value above a predetermined base reference temperature. The predetermined base reference temperature is selected as the maximum temperature at which the device can be operated without temperature being substantially detrimental to life. It has been empirically found that the reduction in life duration is approximately a proportional function of the integrated product of time of overtemperature and the amount of overtemperature above this base temperature value.
In order to accommodate for those situations in which engines are thermally overstressed, resulting from overtemperature operation, actual overhaul intervals have been set somewhat arbitrarily on the short side. When the integrated product of overtemperature and time are recorded for the operation of a particular turbine engine, as by practice of the present invention, overhaul decisions are facilitated. When the accumulated date is made accessible during minor overhauls, engine reliability can be improved by being able to pinpoint abused engines, while the periods between major overhauls on well-treated engines may be extended, with the attendant economic benefits.